The present invention relates to a digital copier having a facsimile transmission and reception capability.
A recent achievement in the imaging art is a digital copier which is the combination of a document reader which digitally reads the image of an original document and laser printer or like page printer which records images page by page with predetermined resolution. This kind of copier has a capability of reproducing images in an edited condition and a capability of processing images themselves as well as a usual copying capability. Further, a digital copier may serve as an output unit of a personal computer or like data processing device for producing hard copies or may even be provided with a communication function to serve as a facsimile terminal.
A problem with a prior art digital copier having a facsimile function is that when the facsimile function is selected, a document having halftone cannot be transmitted in a G2 or G3 mode without sacrificing the image quality due to the change in the size of dots. Specifically, although a prior art facsimile terminal executes halftone processing for the density of 7.7 lines per millimeter, it is incapable of performing halftone processing which accommodates both of the 16 lines per millimeter density and the 7.7 lines per millimeter density by using the same scanner.